Before starting NIV
Testing patients with bulbar impairment
There is evidence that patients with bulbar impairment can still benefit from NIV so they should be considered for a trial.
There are extra considerations to make when carrying out respiratory function tests in patients who have bulbar impairment. Healthcare professionals should be mindful of the factors that influence the decision to carry out respiratory function tests and the difficulties gaining an accurate assessment.
What are some of the factors to consider when carrying out respiratory function tests in patients with bulbar impairment and how might you overcome these in your service?
Some things you should consider:
Ability to do the tests
Concerns surrounding the validity of the tests
Ability to form a seal around the mouthpiece
Impact of pressures on pharynx and larynx
Ability to hold breath by closing the upper airway long enough to do the test
Ability to manage oropharyngeal secretions
Risk of aspiration
To overcome some of the concerns, there are a range of steps that you can take. These include:
Seeking expert help early from respiratory specialists
Using different types of mask and mouthpiece interfaces such as a full face mask
Provide support around the mouth to ensure an adequate seal
Prescribing medication to control oropharyngeal secretions
Monitor for symptoms of respiratory insufficiency more frequently without using respiratory muscle testing
Using alternative tests such as overnight oximetry or polysomnography
Offering a trial of NIV in cases where there is uncertainty
In the following clip, Rosie Whitehead, a Respiratory Physiotherapist, describes the challenges you may face when determining changes in respiratory function.
Challenges determining change in respiratory function
“For some patients, it’s more difficult to know if there’s been changes in their respiratory muscles; those patients that have got a cognitive impairment and they’re not able to tell you the symptoms they’ve noticed or they’re not able to do the breathing tests effectively because they’re quite objective. So we might rely more on a capillary blood gas because that isn’t reliant on the patient reporting things.
For someone who’s got a cognitive impairment, we will rely more on family - are they quite agitated at night, have they noticed they are waking up more, noticed that they are more breathless
Someone that has got quite impaired bulbar function will struggle to do spirometry and will struggle to do a peak cough flow. But it’s looking at: have they noticed their symptoms change, have they noticed that they’re struggling more at nighttime and that might be a sign that they are getting more breathless and their respiratory muscles are weaker.
Again, using the capillary blood gas, like you would with those with a cognitive change, as more of an objective marker and relying more on that than you would the FVC and the spirometry.”
Good practice points
Healthcare professionals should consider the factors influencing the ability to test respiratory function in patients with bulbar impairment and take steps to overcome the barriers.